1. Field of the Invention
The present invention relates to a linear compressor, and, more particularly, to a linear compressor in which an inner core is integrally mounted with a magnet to linearly reciprocate simultaneously and is also mounted on a core frame that comes into close contact with an outer circumference of a cylinder, resulting in improved rigidity and reliability of the compressor.
2. Description of the Related Art
Generally, a linear compressor is an apparatus to suction and compress fluid, such as refrigerant gas (hereinafter referred to as “fluid”), while linearly reciprocating a piston inside a cylinder using a linear driving force of a linear motor to thereby discharge the compressed fluid.
FIG. 1 is a longitudinal sectional view of a conventional linear compressor.
As shown in FIG. 1, the conventional linear compressor includes a shell 4 having a fluid suction pipe 2, a linear compression unit 6 mounted in the shell 4 to compress fluid, and a loop pipe 8 used to discharge the compressed fluid from the linear compression unit 6 to the outside of the shell 4.
The linear compression unit 6 includes a cylinder block 12 centrally provided with a cylinder 10, a rear cover 16 having a fluid suction port 14, a piston 18 inserted in the cylinder 10 to linearly reciprocate inside the cylinder 10, a linear motor 20 adapted to generate a driving force for linearly reciprocating the piston 18 inside the cylinder 10, and a discharge valve assembly 30 mounted at a front side of the cylinder 10 to discharge the compressed fluid from the cylinder 10.
The linear motor is generally divided into a stator and a mover.
The stator includes an outer core 21, an inner core 22 spaced apart from the outer core 21 to define a gap therebetween, a bobbin 23 mounted in the outer core 21, and a coil 24 wound around the bobbin 23 to produce a magnetic field.
The mover includes a magnet 25 interposed between the outer core 21 and the inner core 22 to define gaps with both the outer core 21 and the inner core 22, and a magnet frame 26 to support the magnet 25 affixed thereto.
The piston 18 has a flange portion 28 configured to be affixed to the magnet frame 26. Through the magnet frame 26 and flange portion 28, thereby, a linear movement force of the magnet 25 is transmitted to the piston 18.
Specifically, the magnet 25 is affixed to an outer circumference of the magnet frame 26, and the flange portion 28 of the piston 18 is affixed to an inner end surface of the magnet frame 26.
Now, the operation of the conventional linear compressor configured as stated above will be explained.
Upon driving of the linear motor 20, first, the magnet 25 linearly reciprocates using a magnetic force produced around the coil 24. As the linear reciprocating movement of the magnet 25 is transmitted to the piston 18 via the magnet frame 26, thereby, the piston 18 linearly reciprocates inside the cylinder 10.
According to the linear reciprocating movement of the piston 18, fluid inside the shell 4 is introduced into the cylinder 10 via the fluid suction port 14 of the rear cover 16. After being compressed inside the cylinder 10 by means of the piston 18, the compressed fluid is discharged to the outside of the shell 4 via the discharge valve assembly 30 and the loop pipe 8.
However, the conventional linear compressor is problematic because predetermined gaps must be accurately defined at opposite sides of the magnet 25, that is, between the magnet 25 and the outer core 21 and between the magnet 25 and the inner core 22. This requires a strict tolerance control of the magnet frame 26.